In Japanese Unexamined Patent Application Publication No. 7-131234 (PTL 1), an antenna is illustrated in which two plate-like radiation conductor plates facing each other with a predetermined distance therebetween are formed in a flexible substrate. FIG. 1 is the perspective view of the antenna illustrated in PTL 1.
As illustrated in FIG. 1, along with another plate-like radiation conductor plate 2, a plate-like radiation conductor plate 1 is disposed above one ground conductor plate 3 so as to face the ground conductor plate 3. The two plate-like radiation conductor plates 1 and 2 are formed on a same flexible substrate 4, and a solid dielectric 5 is disposed in place of a spacer between the plate-like radiation conductor plates 1 and 2 and a ground conductor plate 3 so that the two plate-like radiation conductor plates 1 and 2 face the ground conductor plate 3. In addition, power is fed from a feeding point 6 to the plate-like radiation conductor plate 1.
Both of the two plate-like radiation conductor plates 1 and 2 are connected to the ground conductor plate 3 using short circuit conductor plates 7 and 8. In addition, the width and the length including a distance between the plate-like radiation conductor plates 1 and 2 are adjusted so that an adequate double resonance is caused to occur owing to two antennae and a wideband characteristic.
In addition, in Japanese Unexamined Patent Application Publication No. 2003-110346 (PTL 2), a dielectric antenna is disclosed where a feeding electrode is provided on the back surface of a dielectric substrate to capacitively feed power to a radiation electrode on a front surface (top surface). Two radiation electrodes are provided, where one end of each of the two electrodes is connected to a ground.
In addition, in Japanese Unexamined Patent Application Publication No. 11-127014 (PTL 3), a dielectric antenna is disclosed that includes a capacitive feed-type radiation element and two radiation electrodes, one end of each of which is connected to a ground.